Security readout for executives and security teams
Plain-English summary
CVE-2026-21659 affects Johnson Controls Frick Controls Quantum HD refrigeration controllers version 10.22 and prior. A remote unauthenticated attacker could use a local file inclusion flaw to read information and execute code, potentially taking over the device. This is high urgency for sites where these controllers are network reachable.
Executive priority
Treat as a high-priority OT risk assessment item. If affected controllers are reachable beyond tightly controlled networks, prioritize vendor-guided remediation because compromise could affect refrigeration control availability and operational integrity.
Technical view
The issue is a CWE-23 local file inclusion vulnerability in Frick Controls Quantum HD 10.22 and prior. The CVSS 4.0 score is 8.7 with network attack vector, low complexity, no privileges, and no user interaction. The CVE description states arbitrary code execution on the affected device and full system compromise.
Likely exposure
Exposure is most likely where Frick Controls Quantum HD devices version 10.22 or earlier are reachable over networks accessible to attackers. Internet exposure or poorly segmented operational technology networks would increase business risk.
Exploitation context
The provided sources do not state active exploitation, and the CVE is not marked in CISA KEV. However, the vulnerability is unauthenticated, network-accessible, low-complexity, and affects industrial control equipment, making reachable devices important to prioritize.
Researcher notes
Evidence is limited to the CVE record, CISA ICS advisory reference, and Johnson Controls advisory portal. The bundle does not provide specific patch version, workaround text, or exploitation reports. Avoid assuming a fix; validate directly against vendor guidance.
Mitigation direction
- Identify all Frick Controls Quantum HD devices and firmware versions.
- Review Johnson Controls and CISA advisory guidance for approved updates or compensating controls.
- Prioritize remediation for version 10.22 and prior systems with network exposure.
- Limit access to controller management interfaces to trusted operational networks.
- Monitor vendor advisories for updated remediation details.
Validation and detection
- Confirm whether Quantum HD devices are present in asset inventory.
- Verify installed versions against the affected range: 10.22 and prior.
- Check whether affected devices are reachable from untrusted networks.
- Review logs and monitoring for unexpected access to controller interfaces.
- Document remediation status against Johnson Controls and CISA guidance.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-23: File access and web shell behavior lookup
File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-21659 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.7 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N——Primary CVE scoreVulnerability scoring details
Base CVSS 4.0 score
8.7HighVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Source materials
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Relative Path Traversal
Relative Path Traversal represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.